Files
storage-appliance/internal/auth/password.go

90 lines
2.3 KiB
Go

package auth
import (
"crypto/rand"
"crypto/subtle"
"encoding/base64"
"errors"
"fmt"
"strings"
"golang.org/x/crypto/argon2"
)
const (
// Argon2id parameters
argon2Memory = 64 * 1024 // 64 MB
argon2Iterations = 3
argon2Parallelism = 2
argon2SaltLength = 16
argon2KeyLength = 32
)
// HashPassword hashes a password using Argon2id
func HashPassword(password string) (string, error) {
// Generate a random salt
salt := make([]byte, argon2SaltLength)
if _, err := rand.Read(salt); err != nil {
return "", err
}
// Hash the password
hash := argon2.IDKey([]byte(password), salt, argon2Iterations, argon2Memory, argon2Parallelism, argon2KeyLength)
// Encode the hash and salt
b64Salt := base64.RawStdEncoding.EncodeToString(salt)
b64Hash := base64.RawStdEncoding.EncodeToString(hash)
// Return the encoded hash in the format: $argon2id$v=19$m=65536,t=3,p=2$salt$hash
return fmt.Sprintf("$argon2id$v=%d$m=%d,t=%d,p=%d$%s$%s",
argon2.Version, argon2Memory, argon2Iterations, argon2Parallelism, b64Salt, b64Hash), nil
}
// VerifyPassword verifies a password against a hash
func VerifyPassword(password, encodedHash string) (bool, error) {
// Parse the encoded hash
parts := strings.Split(encodedHash, "$")
if len(parts) != 6 {
return false, errors.New("invalid hash format")
}
if parts[1] != "argon2id" {
return false, errors.New("unsupported hash algorithm")
}
// Parse version
var version int
if _, err := fmt.Sscanf(parts[2], "v=%d", &version); err != nil {
return false, err
}
if version != argon2.Version {
return false, errors.New("incompatible version")
}
// Parse parameters
var memory, iterations, parallelism int
if _, err := fmt.Sscanf(parts[3], "m=%d,t=%d,p=%d", &memory, &iterations, &parallelism); err != nil {
return false, err
}
// Decode salt and hash
salt, err := base64.RawStdEncoding.DecodeString(parts[4])
if err != nil {
return false, err
}
hash, err := base64.RawStdEncoding.DecodeString(parts[5])
if err != nil {
return false, err
}
// Compute the hash of the password
otherHash := argon2.IDKey([]byte(password), salt, uint32(iterations), uint32(memory), uint8(parallelism), uint32(len(hash)))
// Compare hashes in constant time
if subtle.ConstantTimeCompare(hash, otherHash) == 1 {
return true, nil
}
return false, nil
}